Scientists discover jet stream in Earth's molten iron core

Representational pic (Courtesy: NASA)

Delhi: A jet stream deep below Earth’s surface has been discovered by scientists using data from the Swarm satellite trio.

The mission found evidence of the underground jet stream nearly 2,000 miles (3000 km) below Earth’s surface, in the liquid iron part of Earth’s core. 

Swarm was launched in 2013 by the European Space Agency (ESA) to study Earth’s magnetic field. 

The trio of satellites simultaneously measure and untangle the different magnetic signals which stem from the Earth's core, mantle, crust, oceans, ionosphere and magnetosphere. 

The results were published on December 19, 2016 in journal 'Nature Geoscience'.

"The European Space Agency's Swarm satellites are providing our sharpest x-ray image yet of the core. We've not only seen this jet stream clearly for the first time, but we understand why it's there," said lead researcher Phil Livermore from the University of Leeds in Britain.

"We can explain it as an accelerating band of molten iron circling the North Pole, like the jet stream in the atmosphere," Livermore added, as per IANS.

Because of the core's remote location under 3,000 kilometres of rock, for many years scientists have studied the Earth's core by measuring the planet's magnetic field - one of the few options available.

Previous research had found that changes in the magnetic field indicated that iron in the outer core was moving faster in the northern hemisphere, mostly under Alaska and Siberia.

But new data from the Swarm satellites revealed these changes are actually caused by a jet stream moving at more than 40 kilometres per year.

The study found the position of the jet stream aligns with a boundary between two different regions in the core. 

The jet is likely to be caused by liquid in the core moving towards this boundary from both sides, which is squeezed out sideways.

(With Agency inputs)